Noticed that when trying to throw the same person multiple times. Since when there are 2 enemies in a level you have to grab the person, throw tehm, re-grab them and then you get the glitched screen. While when you have 4 enemies for example, you need to regrab them 3 times, or grab one and regrab them once, and grab and regrab a second enemies. Either way, one regrab equals one enemy in the level.